Work out firmware update bandwidth instantly with clear inputs, formula shown and shareable results.
Fleet update bandwidth is image size times devices divided by the window, plus about 10% for retries and protocol overhead. Concurrency then sets how long each device has: 5,000 devices in six hours at 50 at a time gives each device just over three minutes.
OTA bandwidth
bandwidth = image size x devices x overhead x 8 / window seconds; per-device time = window x concurrency / devices
Where possible, yes. A binary diff is often 5-20% of a full image, cutting both bandwidth and per-device time by an order of magnitude.
To protect the server and the network, and to keep the blast radius small if the new image proves faulty. Staged rollouts exist for exactly that reason.